I had to get a replacement disc for my 19 1000, after a slight mishap with a disc lock.
after searching for a reasonably priced used one I found that there wasn't much available on the usual auction site, so I found this Cross Reference and managed to source a good used one for a GSX1250 at a much lower price. Got to love the Suzuki parts bin philosophy, anyway here's the link.
msw259 - TRW Automotive Aftermarket Parts
Just click on the OE numbers & linked vehicles button, then Suzuki.